Abstract

Current research is enriching carbon-carbon (C–C) and carbon-hydrogen (C–H) bonds in organic molecules and hydrogen from food wastes, which is blended with 30 % of algae help boost the reaction via supercritical water gasification (SCWG) process and its performance investigated without catalyst and with 1-3 wt% of ruthenium/alumina (Ru/Al2O3) catalyst underwater to biomass ratios of 5:1, which is involved at 25 MPa pressure with 700 °C gasification temperature for 60 min residence time. The influences of catalyst action on molar fraction percentage, syngas yield, carbon gasification efficiency, hydrogen selectivity, and carbon dioxide selectivity are studied in the present research. Based on the investigational results, the 5:1 ratios of water to biomass (70 % food waste/30 % algae booster) processed via SCWG process featured with Ru/Al2O3 catalyst showed the optimum performances and 3 wt% of Ru/Al2O3 catalyst recorded maximum hydrogen (H2) fraction of 74.3 %, reduced carbon dioxide (CO2) fraction of 19.8 %, enhanced H2 yield of 72.3 mol/kg, improved carbon gasification efficiency of 94.6 %, higher H2 selectivity of 90.2 % and decreased CO2 selectivity of 62.5 %. Moreover, combinations of food waste and 30 % of algae processed with the SCWG process, featuring a Ru/Al2O3 catalyst, provide maximum C–C and C–H bonds, resulting in a superior hydrogen yield. © 2025 Hydrogen Energy Publications LLC